Salts of bile acids act as detergents to solubilize and consequently aid in digestion of dietary fats. Bile acids are precursors to bile salts, and are derived from cholesterol. Following digestion, bile acids can be passively absorbed in the jejunum, or, in the case of conjugated primary bile acids, reabsorbed by active transport in the ileum. Bile acids which are not reabsorbed are deconjugated and dehydroxylated by bacterial action in the distal ileum and large intestine.
Reabsorption of bile acids from the intestine conserves lipoprotein cholesterol in the bloodstream. Conversely, blood cholesterol level can be diminished by reducing reabsorption of bile acids.
One method of reducing the amount of bile acids that are reabsorbed is oral administration of compounds that sequester the bile acids and cannot themselves be absorbed. The sequestered bile acids are consequently excreted.
Many bile acid sequestrants, however, do not bind conjugated primary bile acids, such as conjugated cholic and chenodeoxycholic acids well enough to prevent substantial portions from being reabsorbed. In addition, the volume of sequestrants that can be ingested safely is limited. As a result, the effectiveness of sequestrants to diminish blood cholesterol levels is also limited.
A need exists, therefore, for a sequestrant and a method which overcomes or minimizes the referenced problems.